Bug#917500: liggghts: FTBFS (style_atom.h: No such file or directory)

[Santiago Vila]

Small update: I've given Anton Gladky access to a machine where this
seems to happen all the time. (While we are at it: Anybody reading
this willing to debug the problem in the test machine, please contact
me privately and I will gladly give you access as well).

It is interesting to see that this also fails in reproducible-builds:

https://tests.reproducible-builds.org/debian/rbuild/unstable/amd64/liggghts_3.8.0+repack1-2.rbuild.log.gz

but the way it fails is slightly different, and that's why I think it
is a Makefile bug of some kind.

I'm no CMAKE expert at all, but in our test machine, the error message
is like this:

style_atom.h: No such file or directory

So: Where is that style_atom.h file supposed to be generated and how
does the different Makefiles ensure that it's generated *before* it's
actually being used?

Thanks.